text: /*-------------------------------------------------------------------------
   *
   * c.h
   *	  Fundamental C definitions.  This is included by every .c file in
   *	  PostgreSQL (via either postgres.h or postgres_fe.h, as appropriate).
   *
   *	  Note that the definitions here are not intended to be exposed to clients
   *	  of the frontend interface libraries --- so we don't worry much about
   *	  polluting the namespace with lots of stuff...
   *
   *
   * Portions Copyright (c) 2006-2011, Greenplum inc
   * Portions Copyright (c) 2012-Present Pivotal Software, Inc.
   * Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group
   * Portions Copyright (c) 1994, Regents of the University of California
   *
   * src/include/c.h
   *
   *-------------------------------------------------------------------------
   */
  /*
   *----------------------------------------------------------------
   *	 TABLE OF CONTENTS
   *
   *		When adding stuff to this file, please try to put stuff
   *		into the relevant section, or add new sections as appropriate.
   *
   *	  section	description
   *	  -------	------------------------------------------------
   *		0)		pg_config.h and standard system headers
   *		1)		compiler characteristics
   *		2)		bool, true, false, TRUE, FALSE, NULL
   *		3)		standard system types
   *		4)		IsValid macros for system types
   *		5)		offsetof, lengthof, endof, alignment
   *		6)		assertions
   *		7)		widely useful macros
   *		8)		random stuff
   *		9)		system-specific hacks
   *
   * NOTE: since this file is included by both frontend and backend modules, it's
   * almost certainly wrong to put an "extern" declaration here.  typedefs and
   * macros are the kind of thing that might go here.
   *
   *----------------------------------------------------------------
   */
  #ifndef C_H
  #define C_H
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  /*
   * We have to include stdlib.h here because it defines many of these macros
   * on some platforms, and we only want our definitions used if stdlib.h doesn't
   * have its own.  The same goes for stddef and stdarg if present.
   */
  #include "postgres_ext.h"
  
  /* Must undef pg_config_ext.h symbols before including pg_config.h */
  #undef PG_INT64_TYPE
  
  #include "pg_config.h"
  #include "pg_config_manual.h"	/* must be after pg_config.h */
  
  /*
   * We always rely on the WIN32 macro being set by our build system,
   * but _WIN32 is the compiler pre-defined macro. So make sure we define
   * WIN32 whenever _WIN32 is set, to facilitate standalone building.
   */
  #if defined(_WIN32) && !defined(WIN32)
  #define WIN32
  #endif
  
  #if !defined(WIN32) && !defined(__CYGWIN__)		/* win32 includes further down */
  #include "pg_config_os.h"		/* must be before any system header files */
  #endif
  
  #if _MSC_VER >= 1400 || defined(HAVE_CRTDEFS_H)
  #define errcode __msvc_errcode
  #include <crtdefs.h>
  #undef errcode
  #endif
  
  /*
   * We have to include stdlib.h here because it defines many of these macros
   * on some platforms, and we only want our definitions used if stdlib.h doesn't
   * have its own.  The same goes for stddef and stdarg if present.
   */
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <stddef.h>
  #include <stdarg.h>
  #ifdef HAVE_STRINGS_H
  #include <strings.h>
  #endif
  #ifdef HAVE_STDINT_H
  #include <stdint.h>
  #endif
  #include <sys/types.h>
  #include <errno.h>
  #if defined(WIN32) || defined(__CYGWIN__)
  #include <fcntl.h>				/* ensure O_BINARY is available */
  #endif
  #include <locale.h>
  #ifdef ENABLE_NLS
  #include <libintl.h>
  #endif
  
  #if defined(WIN32) || defined(__CYGWIN__)
  /* We have to redefine some system functions after they are included above. */
  #include "pg_config_os.h"
  #endif
  
  
  /* ----------------------------------------------------------------
   *				Section 1: compiler characteristics
   *
   * type prefixes (const, signed, volatile, inline) are handled in pg_config.h.
   * ----------------------------------------------------------------
   */
  
  /*
   * Disable "inline" if PG_FORCE_DISABLE_INLINE is defined.
   * This is used to work around compiler bugs and might also be useful for
   * investigatory purposes.
   */
  #ifdef PG_FORCE_DISABLE_INLINE
  #undef inline
  #define inline
  #endif
  
  /*
   * Attribute macros
   *
   * GCC: https://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html
   * GCC: https://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html
   * Sunpro: https://docs.oracle.com/cd/E18659_01/html/821-1384/gjzke.html
   * XLC: http://www-01.ibm.com/support/knowledgecenter/SSGH2K_11.1.0/com.ibm.xlc111.aix.doc/language_ref/function_attributes.html
   * XLC: http://www-01.ibm.com/support/knowledgecenter/SSGH2K_11.1.0/com.ibm.xlc111.aix.doc/language_ref/type_attrib.html
   */
  
  /* only GCC supports the unused attribute */
  #ifdef __GNUC__
  #define pg_attribute_unused() __attribute__((unused))
  #else
  #define pg_attribute_unused()
  #endif
  
  /*
   * Append PG_USED_FOR_ASSERTS_ONLY to definitions of variables that are only
   * used in assert-enabled builds, to avoid compiler warnings about unused
   * variables in assert-disabled builds.
   */
  #ifdef USE_ASSERT_CHECKING
  #define PG_USED_FOR_ASSERTS_ONLY
  #else
  #define PG_USED_FOR_ASSERTS_ONLY pg_attribute_unused()
  #endif
  
  /* GCC and XLC support format attributes */
  #if defined(__GNUC__) || defined(__IBMC__)
  #define pg_attribute_format_arg(a) __attribute__((format_arg(a)))
  #define pg_attribute_printf(f,a) __attribute__((format(PG_PRINTF_ATTRIBUTE, f, a)))
  #else
  #define pg_attribute_format_arg(a)
  #define pg_attribute_printf(f,a)
  #endif
  
  /* GCC, Sunpro and XLC support aligned, packed and noreturn */
  #if defined(__GNUC__) || defined(__SUNPRO_C) || defined(__IBMC__)
  #define pg_attribute_aligned(a) __attribute__((aligned(a)))
  #define pg_attribute_noreturn() __attribute__((noreturn))
  #define pg_attribute_packed() __attribute__((packed))
  #define HAVE_PG_ATTRIBUTE_NORETURN 1
  #else
  /*
   * NB: aligned and packed are not given default definitions because they
   * affect code functionality; they *must* be implemented by the compiler
   * if they are to be used.
   */
  #define pg_attribute_noreturn()
  #endif
  
  /*
   * Forcing a function not to be inlined can be useful if it's the slow path of
   * a performance-critical function, or should be visible in profiles to allow
   * for proper cost attribution.  Note that unlike the pg_attribute_XXX macros
   * above, this should be placed before the function's return type and name.
   */
  /* GCC, Sunpro and XLC support noinline via __attribute__ */
  #if (defined(__GNUC__) && __GNUC__ > 2) || defined(__SUNPRO_C) || defined(__IBMC__)
  #define pg_noinline __attribute__((noinline))
  /* msvc via declspec */
  #elif defined(_MSC_VER)
  #define pg_noinline __declspec(noinline)
  #else
  #define pg_noinline
  #endif
  
  /*
   * Mark a point as unreachable in a portable fashion.  This should preferably
   * be something that the compiler understands, to aid code generation.
   * In assert-enabled builds, we prefer abort() for debugging reasons.
   */
  #if defined(HAVE__BUILTIN_UNREACHABLE) && !defined(USE_ASSERT_CHECKING)
  #define pg_unreachable() __builtin_unreachable()
  #elif defined(_MSC_VER) && !defined(USE_ASSERT_CHECKING)
  #define pg_unreachable() __assume(0)
  #else
  #define pg_unreachable() abort()
  #endif
  
  /*
   * Hints to the compiler about the likelihood of a branch. Both likely() and
   * unlikely() return the boolean value of the contained expression.
   *
   * These should only be used sparingly, in very hot code paths. It's very easy
   * to mis-estimate likelihoods.
   */
  #if __GNUC__ >= 3
  #define likely(x)	__builtin_expect((x) != 0, 1)
  #define unlikely(x) __builtin_expect((x) != 0, 0)
  #else
  #define likely(x)	((x) != 0)
  #define unlikely(x) ((x) != 0)
  #endif
  
  /*
   * CppAsString
   *		Convert the argument to a string, using the C preprocessor.
   * CppConcat
   *		Concatenate two arguments together, using the C preprocessor.
   *
   * Note: There used to be support here for pre-ANSI C compilers that didn't
   * support # and ##.  Nowadays, these macros are just for clarity and/or
   * backward compatibility with existing PostgreSQL code.
   */
  #define CppAsString(identifier) #identifier
  #define CppConcat(x, y)			x##y
  
  /*
   * dummyret is used to set return values in macros that use ?: to make
   * assignments.  gcc wants these to be void, other compilers like char
   */
  #ifdef __GNUC__					/* GNU cc */
  #define dummyret	void
  #else
  #define dummyret	char
  #endif
  
  #ifndef __GNUC__
  #define __attribute__(_arg_)
  #endif
  
  
  /* ----------------------------------------------------------------
   *				Section 2:	bool, true, false, TRUE, FALSE, NULL
   * ----------------------------------------------------------------
   */
  
  /*
   * bool
   *		Boolean value, either true or false.
   *
   * XXX for C++ compilers, we assume the compiler has a compatible
   * built-in definition of bool.
   */
  
  #ifndef __cplusplus
  
  #ifndef bool
  typedef char bool;
  #endif
  
  #ifndef true
  #define true	((bool) 1)
  #endif
  
  #ifndef false
  #define false	((bool) 0)
  #endif
  
  #endif   /* not C++ */
  
  typedef bool *BoolPtr;
  
  #ifndef TRUE
  #define TRUE	1
  #endif
  
  #ifndef FALSE
  #define FALSE	0
  #endif
  
  /*
   * NULL
   *		Null pointer.
   */
  #ifndef NULL
  #define NULL	((void *) 0)
  #endif
  
  
  /* ----------------------------------------------------------------
   *				Section 3:	standard system types
   * ----------------------------------------------------------------
   */
  
  /*
   * Pointer
   *		Variable holding address of any memory resident object.
   *
   *		XXX Pointer arithmetic is done with this, so it can't be void *
   *		under "true" ANSI compilers.
   */
  typedef char *Pointer;
  
  /*
   * intN
   *		Signed integer, EXACTLY N BITS IN SIZE,
   *		used for numerical computations and the
   *		frontend/backend protocol.
   */
  #ifndef HAVE_INT8
  typedef signed char int8;		/* == 8 bits */
  typedef signed short int16;		/* == 16 bits */
  typedef signed int int32;		/* == 32 bits */
  #endif   /* not HAVE_INT8 */
  
  /*
   * uintN
   *		Unsigned integer, EXACTLY N BITS IN SIZE,
   *		used for numerical computations and the
   *		frontend/backend protocol.
   */
  #ifndef HAVE_UINT8
  typedef unsigned char uint8;	/* == 8 bits */
  typedef unsigned short uint16;	/* == 16 bits */
  typedef unsigned int uint32;	/* == 32 bits */
  #endif   /* not HAVE_UINT8 */
  
  /*
   * bitsN
   *		Unit of bitwise operation, AT LEAST N BITS IN SIZE.
   */
  typedef uint8 bits8;			/* >= 8 bits */
  typedef uint16 bits16;			/* >= 16 bits */
  typedef uint32 bits32;			/* >= 32 bits */
  
  /*
   * 64-bit integers
   */
  #ifdef HAVE_LONG_INT_64
  /* Plain "long int" fits, use it */
  
  #ifndef HAVE_INT64
  typedef long int int64;
  #endif
  #ifndef HAVE_UINT64
  typedef unsigned long int uint64;
  #endif
  #define INT64CONST(x)  (x##L)
  #define UINT64CONST(x) (x##UL)
  #elif defined(HAVE_LONG_LONG_INT_64)
  /* We have working support for "long long int", use that */
  
  #ifndef HAVE_INT64
  typedef long long int int64;
  #endif
  #ifndef HAVE_UINT64
  typedef unsigned long long int uint64;
  #endif
  #define INT64CONST(x)  (x##LL)
  #define UINT64CONST(x) (x##ULL)
  #else
  /* neither HAVE_LONG_INT_64 nor HAVE_LONG_LONG_INT_64 */
  #error must have a working 64-bit integer datatype
  #endif
  
  /* Max value of size_t might be missing if we don't have stdint.h */
  #ifndef SIZE_MAX
  #if SIZEOF_SIZE_T == 8
  #define SIZE_MAX UINT64CONST(0xFFFFFFFFFFFFFFFF)
  #else
  #define SIZE_MAX (0xFFFFFFFFU)
  #endif
  #endif
  
  /*
   * stdint.h limits aren't guaranteed to be present and aren't guaranteed to
   * have compatible types with our fixed width types. So just define our own.
   */
  #define PG_INT8_MIN     (-0x7F-1)
  #define PG_INT8_MAX     (0x7F)
  #define PG_UINT8_MAX    (0xFF)
  #define PG_INT16_MIN    (-0x7FFF-1)
  #define PG_INT16_MAX    (0x7FFF)
  #define PG_UINT16_MAX   (0xFFFF)
  #define PG_INT32_MIN    (-0x7FFFFFFF-1)
  #define PG_INT32_MAX    (0x7FFFFFFF)
  #define PG_UINT32_MAX   (0xFFFFFFFF)
  #define PG_INT64_MIN    (-INT64CONST(0x7FFFFFFFFFFFFFFF) - 1)
  #define PG_INT64_MAX    INT64CONST(0x7FFFFFFFFFFFFFFF)
  #define PG_UINT64_MAX   UINT64CONST(0xFFFFFFFFFFFFFFFF)
  
  /* Select timestamp representation (float8 or int64) */
  #ifdef USE_INTEGER_DATETIMES
  #define HAVE_INT64_TIMESTAMP
  #endif
  
  /*
   * 128-bit signed and unsigned integers
   *		There currently is only limited support for such types.
   *		E.g. 128bit literals and snprintf are not supported; but math is.
   *		Also, because we exclude such types when choosing MAXIMUM_ALIGNOF,
   *		it must be possible to coerce the compiler to allocate them on no
   *		more than MAXALIGN boundaries.
   */
  #if defined(PG_INT128_TYPE)
  #if defined(pg_attribute_aligned) || ALIGNOF_PG_INT128_TYPE <= MAXIMUM_ALIGNOF
  #define HAVE_INT128 1
  
  typedef PG_INT128_TYPE int128
  #if defined(pg_attribute_aligned)
  pg_attribute_aligned(MAXIMUM_ALIGNOF)
  #endif
  ;
  
  typedef unsigned PG_INT128_TYPE uint128
  #if defined(pg_attribute_aligned)
  pg_attribute_aligned(MAXIMUM_ALIGNOF)
  #endif
  ;
  
  #endif
  #endif
  
  /* sig_atomic_t is required by ANSI C, but may be missing on old platforms */
  #ifndef HAVE_SIG_ATOMIC_T
  typedef int sig_atomic_t;
  #endif
  
  /*
   * Size
   *		Size of any memory resident object, as returned by sizeof.
   */
  typedef size_t Size;
  
  /*
   * Index
   *		Index into any memory resident array.
   *
   * Note:
   *		Indices are non negative.
   */
  typedef unsigned int Index;
  
  /*
   * Offset
   *		Offset into any memory resident array.
   *
   * Note:
   *		This differs from an Index in that an Index is always
   *		non negative, whereas Offset may be negative.
   */
  typedef signed int Offset;
  
  /*
   * Common Postgres datatype names (as used in the catalogs)
   */
  typedef float float4;
  typedef double float8;
  
  /*
   * Oid, RegProcedure, TransactionId, SubTransactionId, MultiXactId,
   * CommandId
   */
  
  /* typedef Oid is in postgres_ext.h */
  
  /*
   * regproc is the type name used in the include/catalog headers, but
   * RegProcedure is the preferred name in C code.
   */
  typedef Oid regproc;
  typedef regproc RegProcedure;
  
  typedef uint32 TransactionId;
  
  typedef uint32 LocalTransactionId;
  
  typedef uint32 SubTransactionId;
  
  #define InvalidSubTransactionId		((SubTransactionId) 0)
  #define TopSubTransactionId			((SubTransactionId) 1)
  
  /* MultiXactId must be equivalent to TransactionId, to fit in t_xmax */
  typedef TransactionId MultiXactId;
  
  typedef uint32 MultiXactOffset;
  
  typedef uint32 DistributedTransactionTimeStamp;
  
  typedef int32 DistributedSnapshotId;
  
  typedef uint32 DistributedTransactionId;
  #define InvalidDistributedTransactionId	((DistributedTransactionId) 0)
  #define FirstDistributedTransactionId	((DistributedTransactionId) 1)
  #define LastDistributedTransactionId	((DistributedTransactionId) 0xffffffff)
  
  /*
   * A 10 digit timestamp, a dash, a 10 digit distributed transaction id, and NUL.
   */
  #define TMGIDSIZE 22
  
  typedef uint32 CommandId;
  
  typedef int32  gpsegmentId;        /* CDB: type of gp_segment_id system col */
  
  #define FirstCommandId	((CommandId) 0)
  #define InvalidCommandId	(~(CommandId)0)
  
  /*
   * Array indexing support
   */
  #define MAXDIM 6
  typedef struct
  {
  	int			indx[MAXDIM];
  } IntArray;
  
  /* ----------------
   *		Variable-length datatypes all share the 'struct varlena' header.
   *
   * NOTE: for TOASTable types, this is an oversimplification, since the value
   * may be compressed or moved out-of-line.  However datatype-specific routines
   * are mostly content to deal with de-TOASTed values only, and of course
   * client-side routines should never see a TOASTed value.  But even in a
   * de-TOASTed value, beware of touching vl_len_ directly, as its representation
   * is no longer convenient.  It's recommended that code always use the VARDATA,
   * VARSIZE, and SET_VARSIZE macros instead of relying on direct mentions of
   * the struct fields.  See postgres.h for details of the TOASTed form.
   * ----------------
   */
  struct varlena
  {
  	char		vl_len_[4];		/* Do not touch this field directly! */
  	char		vl_dat[1];
  };
  
  #define VARHDRSZ		((int32) sizeof(int32))
  
  /*
   * These widely-used datatypes are just a varlena header and the data bytes.
   * There is no terminating null or anything like that --- the data length is
   * always VARSIZE(ptr) - VARHDRSZ.
   */
  typedef struct varlena bytea;
  typedef struct varlena text;
  typedef struct varlena BpChar;	/* blank-padded char, ie SQL char(n) */
  typedef struct varlena VarChar; /* var-length char, ie SQL varchar(n) */
  
  /*
   * Specialized array types.  These are physically laid out just the same
   * as regular arrays (so that the regular array subscripting code works
   * with them).  They exist as distinct types mostly for historical reasons:
   * they have nonstandard I/O behavior which we don't want to change for fear
   * of breaking applications that look at the system catalogs.  There is also
   * an implementation issue for oidvector: it's part of the primary key for
   * pg_proc, and we can't use the normal btree array support routines for that
   * without circularity.
   */
  typedef struct
  {
  	int32		vl_len_;		/* these fields must match ArrayType! */
  	int			ndim;			/* always 1 for int2vector */
  	int32		dataoffset;		/* always 0 for int2vector */
  	Oid			elemtype;
  	int			dim1;
  	int			lbound1;
  	int16		values[1];		/* VARIABLE LENGTH ARRAY */
  } int2vector;					/* VARIABLE LENGTH STRUCT */
  
  typedef struct
  {
  	int32		vl_len_;		/* these fields must match ArrayType! */
  	int			ndim;			/* always 1 for oidvector */
  	int32		dataoffset;		/* always 0 for oidvector */
  	Oid			elemtype;
  	int			dim1;
  	int			lbound1;
  	Oid			values[1];		/* VARIABLE LENGTH ARRAY */
  } oidvector;					/* VARIABLE LENGTH STRUCT */
  
  /*
   * Representation of a Name: effectively just a C string, but null-padded to
   * exactly NAMEDATALEN bytes.  The use of a struct is historical.
   */
  typedef struct nameData
  {
  	char		data[NAMEDATALEN];
  } NameData;
  typedef NameData *Name;
  
  #define NameStr(name)	((name).data)
  
  
  /* ----------------------------------------------------------------
   *				Section 4:	IsValid macros for system types
   * ----------------------------------------------------------------
   */
  /*
   * BoolIsValid
   *		True iff bool is valid.
   */
  #define BoolIsValid(boolean)	((boolean) == false || (boolean) == true)
  
  /*
   * PointerIsValid
   *		True iff pointer is valid.
   */
  #define PointerIsValid(pointer) ((const void*)(pointer) != NULL)
  
  /*
   * PointerIsAligned
   *		True iff pointer is properly aligned to point to the given type.
   */
  #define PointerIsAligned(pointer, type) \
  		(((uintptr_t)(pointer) % (sizeof (type))) == 0)
  
  #define OidIsValid(objectId)  ((bool) ((objectId) != InvalidOid))
  
  #define RegProcedureIsValid(p)	OidIsValid(p)
  
  
  /* ----------------------------------------------------------------
   *				Section 5:	offsetof, lengthof, endof, alignment
   * ----------------------------------------------------------------
   */
  /*
   * offsetof
   *		Offset of a structure/union field within that structure/union.
   *
   *		XXX This is supposed to be part of stddef.h, but isn't on
   *		some systems (like SunOS 4).
   */
  #ifndef offsetof
  #define offsetof(type, field)	((long) &((type *)0)->field)
  #endif   /* offsetof */
  
  /*
   * lengthof
   *		Number of elements in an array.
   */
  #define lengthof(array) (sizeof (array) / sizeof ((array)[0]))
  
  /*
   * endof
   *		Address of the element one past the last in an array.
   */
  #define endof(array)	(&(array)[lengthof(array)])
  
  /* ----------------
   * Alignment macros: align a length or address appropriately for a given type.
   * The fooALIGN() macros round up to a multiple of the required alignment,
   * while the fooALIGN_DOWN() macros round down.  The latter are more useful
   * for problems like "how many X-sized structures will fit in a page?".
   *
   * NOTE: TYPEALIGN[_DOWN] will not work if ALIGNVAL is not a power of 2.
   * That case seems extremely unlikely to be needed in practice, however.
   *
   * NOTE: MAXIMUM_ALIGNOF, and hence MAXALIGN(), intentionally exclude any
   * larger-than-8-byte types the compiler might have.
   * ----------------
   */
  
  #define TYPEALIGN(ALIGNVAL,LEN)  \
  	(((uintptr_t) (LEN) + ((ALIGNVAL) - 1)) & ~((uintptr_t) ((ALIGNVAL) - 1)))
  
  #define SHORTALIGN(LEN)			TYPEALIGN(ALIGNOF_SHORT, (LEN))
  #define INTALIGN(LEN)			TYPEALIGN(ALIGNOF_INT, (LEN))
  #define LONGALIGN(LEN)			TYPEALIGN(ALIGNOF_LONG, (LEN))
  #define DOUBLEALIGN(LEN)		TYPEALIGN(ALIGNOF_DOUBLE, (LEN))
  #define MAXALIGN(LEN)			TYPEALIGN(MAXIMUM_ALIGNOF, (LEN))
  /* MAXALIGN covers only built-in types, not buffers */
  #define BUFFERALIGN(LEN)		TYPEALIGN(ALIGNOF_BUFFER, (LEN))
  
  #define TYPEALIGN_DOWN(ALIGNVAL,LEN)  \
  	(((uintptr_t) (LEN)) & ~((uintptr_t) ((ALIGNVAL) - 1)))
  
  #define SHORTALIGN_DOWN(LEN)	TYPEALIGN_DOWN(ALIGNOF_SHORT, (LEN))
  #define INTALIGN_DOWN(LEN)		TYPEALIGN_DOWN(ALIGNOF_INT, (LEN))
  #define LONGALIGN_DOWN(LEN)		TYPEALIGN_DOWN(ALIGNOF_LONG, (LEN))
  #define DOUBLEALIGN_DOWN(LEN)	TYPEALIGN_DOWN(ALIGNOF_DOUBLE, (LEN))
  #define MAXALIGN_DOWN(LEN)		TYPEALIGN_DOWN(MAXIMUM_ALIGNOF, (LEN))
  
  /*
   * The above macros will not work with types wider than uintptr_t, like with
   * uint64 on 32-bit platforms.  That's not problem for the usual use where a
   * pointer or a length is aligned, but for the odd case that you need to
   * align something (potentially) wider, use TYPEALIGN64.
   */
  #define TYPEALIGN64(ALIGNVAL,LEN)  \
  	(((uint64) (LEN) + ((ALIGNVAL) - 1)) & ~((uint64) ((ALIGNVAL) - 1)))
  
  /* we don't currently need wider versions of the other ALIGN macros */
  #define MAXALIGN64(LEN)			TYPEALIGN64(MAXIMUM_ALIGNOF, (LEN))
  
  
  /* ----------------------------------------------------------------
   *				Section 6:	assertions
   * ----------------------------------------------------------------
   */
  
  /*
   * USE_ASSERT_CHECKING, if defined, turns on all the assertions.
   * - plai  9/5/90
   *
   * It should _NOT_ be defined in releases or in benchmark copies
   */
  
  /*
   * Assert() can be used in both frontend and backend code. In frontend code it
   * just calls the standard assert, if it's available. If use of assertions is
   * not configured, it does nothing.
   */
  #ifndef USE_ASSERT_CHECKING
  
  #define Assert(condition)	((void)true)
  #define AssertMacro(condition)	((void)true)
  #define AssertArg(condition)	((void)true)
  #define AssertState(condition)	((void)true)
  #define AssertPointerAlignment(ptr, bndr)	((void)true)
  #define AssertImply(condition1, condition2)	((void)true)
  #define AssertEquivalent(cond1, cond2)	((void)true)
  #define Trap(condition, errorType)	((void)true)
  #define TrapMacro(condition, errorType) (true)
  
  #elif defined(FRONTEND)
  
  #include <assert.h>
  #define Assert(p) assert(p)
  #define AssertMacro(p)	((void) assert(p))
  #define AssertArg(condition) assert(condition)
  #define AssertState(condition) assert(condition)
  #define AssertPointerAlignment(ptr, bndr)	((void)true)
  #define Trap(condition, errorType) \
  	do { \
  		(void) assert(!(condition)); \
  	} while (0)
  #define TrapMacro(condition, errorType) \
  	((bool) (assert(!(condition)), 0))
  
  #else							/* USE_ASSERT_CHECKING && !FRONTEND */
  
  /*
   * Trap
   *		Generates an exception if the given condition is true.
   */
  #define Trap(condition, errorType) \
  	do { \
  		if ((assert_enabled) && (condition)) \
  			ExceptionalCondition(CppAsString(condition), (errorType), \
  								 __FILE__, __LINE__); \
  	} while (0)
  
  /*
   *	TrapMacro is the same as Trap but it's intended for use in macros:
   *
   *		#define foo(x) (AssertMacro(x != 0), bar(x))
   *
   *	Isn't CPP fun?
   */
  #define TrapMacro(condition, errorType) \
  	((bool) ((! assert_enabled) || ! (condition) || \
  			 (ExceptionalCondition(CppAsString(condition), (errorType), \
  								   __FILE__, __LINE__), 0)))
  
  #define Assert(condition) \
  		Trap(!(condition), "FailedAssertion")
  
  #define AssertMacro(condition) \
  		((void) TrapMacro(!(condition), "FailedAssertion"))
  
  #define AssertArg(condition) \
  		Trap(!(condition), "BadArgument")
  
  #define AssertState(condition) \
  		Trap(!(condition), "BadState")
  
  #define AssertImply(cond1, cond2) \
  		Trap(!(!(cond1) || (cond2)), "AssertImply failed")
  
  #define AssertEquivalent(cond1, cond2) \
  		Trap(!((bool)(cond1) == (bool)(cond2)), "AssertEquivalent failed")
  
  /*
   * Check that `ptr' is `bndr' aligned.
   */
  #define AssertPointerAlignment(ptr, bndr) \
  	Trap(TYPEALIGN(bndr, (uintptr_t)(ptr)) != (uintptr_t)(ptr), \
  		 "UnalignedPointer")
  
  #endif   /* USE_ASSERT_CHECKING && !FRONTEND */
  
  
  /*
   * Macros to support compile-time assertion checks.
   *
   * If the "condition" (a compile-time-constant expression) evaluates to false,
   * throw a compile error using the "errmessage" (a string literal).
   *
   * gcc 4.6 and up supports _Static_assert(), but there are bizarre syntactic
   * placement restrictions.  These macros make it safe to use as a statement
   * or in an expression, respectively.
   *
   * Otherwise we fall back on a kluge that assumes the compiler will complain
   * about a negative width for a struct bit-field.  This will not include a
   * helpful error message, but it beats not getting an error at all.
   */
  #ifdef HAVE__STATIC_ASSERT
  #define StaticAssertStmt(condition, errmessage) \
  	do { _Static_assert(condition, errmessage); } while(0)
  #define StaticAssertExpr(condition, errmessage) \
  	({ StaticAssertStmt(condition, errmessage); true; })
  #else							/* !HAVE__STATIC_ASSERT */
  #define StaticAssertStmt(condition, errmessage) \
  	((void) sizeof(struct { int static_assert_failure : (condition) ? 1 : -1; }))
  #define StaticAssertExpr(condition, errmessage) \
  	StaticAssertStmt(condition, errmessage)
  #endif   /* HAVE__STATIC_ASSERT */
  
  
  /*
   * Compile-time checks that a variable (or expression) has the specified type.
   *
   * AssertVariableIsOfType() can be used as a statement.
   * AssertVariableIsOfTypeMacro() is intended for use in macros, eg
   *		#define foo(x) (AssertVariableIsOfTypeMacro(x, int), bar(x))
   *
   * If we don't have __builtin_types_compatible_p, we can still assert that
   * the types have the same size.  This is far from ideal (especially on 32-bit
   * platforms) but it provides at least some coverage.
   */
  #ifdef HAVE__BUILTIN_TYPES_COMPATIBLE_P
  #define AssertVariableIsOfType(varname, typename) \
  	StaticAssertStmt(__builtin_types_compatible_p(__typeof__(varname), typename), \
  	CppAsString(varname) " does not have type " CppAsString(typename))
  #define AssertVariableIsOfTypeMacro(varname, typename) \
  	((void) StaticAssertExpr(__builtin_types_compatible_p(__typeof__(varname), typename), \
  	 CppAsString(varname) " does not have type " CppAsString(typename)))
  #else							/* !HAVE__BUILTIN_TYPES_COMPATIBLE_P */
  #define AssertVariableIsOfType(varname, typename) \
  	StaticAssertStmt(sizeof(varname) == sizeof(typename), \
  	CppAsString(varname) " does not have type " CppAsString(typename))
  #define AssertVariableIsOfTypeMacro(varname, typename) \
  	((void) StaticAssertExpr(sizeof(varname) == sizeof(typename),		\
  	 CppAsString(varname) " does not have type " CppAsString(typename)))
  #endif   /* HAVE__BUILTIN_TYPES_COMPATIBLE_P */
  
  
  /* ----------------------------------------------------------------
   *				Section 7:	widely useful macros
   * ----------------------------------------------------------------
   */
  /*
   * Max
   *		Return the maximum of two numbers.
   */
  #define Max(x, y)		((x) > (y) ? (x) : (y))
  
  /*
   * Min
   *		Return the minimum of two numbers.
   */
  #define Min(x, y)		((x) < (y) ? (x) : (y))
  
  /*
   * Abs
   *		Return the absolute value of the argument.
   */
  #define Abs(x)			((x) >= 0 ? (x) : -(x))
  
  /*
   * StrNCpy
   *	Like standard library function strncpy(), except that result string
   *	is guaranteed to be null-terminated --- that is, at most N-1 bytes
   *	of the source string will be kept.
   *	Also, the macro returns no result (too hard to do that without
   *	evaluating the arguments multiple times, which seems worse).
   *
   *	BTW: when you need to copy a non-null-terminated string (like a text
   *	datum) and add a null, do not do it with StrNCpy(..., len+1).  That
   *	might seem to work, but it fetches one byte more than there is in the
   *	text object.  One fine day you'll have a SIGSEGV because there isn't
   *	another byte before the end of memory.  Don't laugh, we've had real
   *	live bug reports from real live users over exactly this mistake.
   *	Do it honestly with "memcpy(dst,src,len); dst[len] = '\0';", instead.
   */
  #define StrNCpy(dst,src,len) \
  	do \
  	{ \
  		char * _dst = (dst); \
  		Size _len = (len); \
  \
  		if (_len > 0) \
  		{ \
  			strncpy(_dst, (src), _len); \
  			_dst[_len-1] = '\0'; \
  		} \
  	} while (0)
  
  
  /* Get a bit mask of the bits set in non-long aligned addresses */
  #define LONG_ALIGN_MASK (sizeof(long) - 1)
  
  /*
   * MemSet
   *	Exactly the same as standard library function memset(), but considerably
   *	faster for zeroing small word-aligned structures (such as parsetree nodes).
   *	This has to be a macro because the main point is to avoid function-call
   *	overhead.   However, we have also found that the loop is faster than
   *	native libc memset() on some platforms, even those with assembler
   *	memset() functions.  More research needs to be done, perhaps with
   *	MEMSET_LOOP_LIMIT tests in configure.
   */
  #define MemSet(start, val, len) \
  	do \
  	{ \
  		/* must be void* because we don't know if it is integer aligned yet */ \
  		void   *_vstart = (void *) (start); \
  		int		_val = (val); \
  		Size	_len = (len); \
  \
  		if ((((uintptr_t) _vstart) & LONG_ALIGN_MASK) == 0 && \
  			(_len & LONG_ALIGN_MASK) == 0 && \
  			_val == 0 && \
  			_len <= MEMSET_LOOP_LIMIT && \
  			/* \
  			 *	If MEMSET_LOOP_LIMIT == 0, optimizer should find \
  			 *	the whole "if" false at compile time. \
  			 */ \
  			MEMSET_LOOP_LIMIT != 0) \
  		{ \
  			long *_start = (long *) _vstart; \
  			long *_stop = (long *) ((char *) _start + _len); \
  			while (_start < _stop) \
  				*_start++ = 0; \
  		} \
  		else \
  			memset(_vstart, _val, _len); \
  	} while (0)
  
  /*
   * MemSetAligned is the same as MemSet except it omits the test to see if
   * "start" is word-aligned.  This is okay to use if the caller knows a-priori
   * that the pointer is suitably aligned (typically, because he just got it
   * from palloc(), which always delivers a max-aligned pointer).
   */
  #define MemSetAligned(start, val, len) \
  	do \
  	{ \
  		long   *_start = (long *) (start); \
  		int		_val = (val); \
  		Size	_len = (len); \
  \
  		if ((_len & LONG_ALIGN_MASK) == 0 && \
  			_val == 0 && \
  			_len <= MEMSET_LOOP_LIMIT && \
  			MEMSET_LOOP_LIMIT != 0) \
  		{ \
  			long *_stop = (long *) ((char *) _start + _len); \
  			while (_start < _stop) \
  				*_start++ = 0; \
  		} \
  		else \
  			memset(_start, _val, _len); \
  	} while (0)
  
  
  /*
   * MemSetTest/MemSetLoop are a variant version that allow all the tests in
   * MemSet to be done at compile time in cases where "val" and "len" are
   * constants *and* we know the "start" pointer must be word-aligned.
   * If MemSetTest succeeds, then it is okay to use MemSetLoop, otherwise use
   * MemSetAligned.  Beware of multiple evaluations of the arguments when using
   * this approach.
   */
  #define MemSetTest(val, len) \
  	( ((len) & LONG_ALIGN_MASK) == 0 && \
  	(len) <= MEMSET_LOOP_LIMIT && \
  	MEMSET_LOOP_LIMIT != 0 && \
  	(val) == 0 )
  
  #define MemSetLoop(start, val, len) \
  	do \
  	{ \
  		long * _start = (long *) (start); \
  		long * _stop = (long *) ((char *) _start + (Size) (len)); \
  	\
  		while (_start < _stop) \
  			*_start++ = 0; \
  	} while (0)
  
  
  /*
   * UnusedArg
   *  Silence the compiler's warning about an unreferenced parameter or variable.
   *
   *  int f(int x)
   *  {
   *      int result = 1;
   *      UnusedArg(x);
   *      return result;
   *  }
   */
  #define UnusedArg(arg)    ((void)(arg))
  
  /*
   * Function inlining support -- Allow modules to define functions that may be
   * inlined, if the compiler supports it.
   *
   * The function bodies must be defined in the module header prefixed by
   * STATIC_IF_INLINE, protected by a cpp symbol that the module's .c file must
   * define.  If the compiler doesn't support inline functions, the function
   * definitions are pulled in by the .c file as regular (not inline) symbols.
   *
   * The header must also declare the functions' prototypes, protected by
   * !PG_USE_INLINE.
   */
  
  
  /* declarations which are only visible when not inlining and in the .c file */
  #ifdef PG_USE_INLINE
  #define STATIC_IF_INLINE static inline
  #else
  #define STATIC_IF_INLINE
  #endif   /* PG_USE_INLINE */
  
  /* declarations which are marked inline when inlining, extern otherwise */
  #ifdef PG_USE_INLINE
  #define STATIC_IF_INLINE_DECLARE static inline
  #else
  #define STATIC_IF_INLINE_DECLARE extern
  #endif   /* PG_USE_INLINE */
  
  
  /* ----------------------------------------------------------------
   *				Section 8:	random stuff
   * ----------------------------------------------------------------
   */
  
  /*
   * Invert the sign of a qsort-style comparison result, ie, exchange negative
   * and positive integer values, being careful not to get the wrong answer
   * for INT_MIN.  The argument should be an integral variable.
   */
  #define INVERT_COMPARE_RESULT(var) \
  	((var) = ((var) < 0) ? 1 : -(var))
  
  /*
   * Use this, not "char buf[BLCKSZ]", to declare a field or local variable
   * holding a page buffer, if that page might be accessed as a page and not
   * just a string of bytes.  Otherwise the variable might be under-aligned,
   * causing problems on alignment-picky hardware.  (In some places, we use
   * this to declare buffers even though we only pass them to read() and
   * write(), because copying to/from aligned buffers is usually faster than
   * using unaligned buffers.)  We include both "double" and "int64" in the
   * union to ensure that the compiler knows the value must be MAXALIGN'ed
   * (cf. configure's computation of MAXIMUM_ALIGNOF).
   */
  typedef union PGAlignedBlock
  {
  	char		data[BLCKSZ];
  	double		force_align_d;
  	int64		force_align_i64;
  } PGAlignedBlock;
  
  /* Same, but for an XLOG_BLCKSZ-sized buffer */
  typedef union PGAlignedXLogBlock
  {
  	char		data[XLOG_BLCKSZ];
  	double		force_align_d;
  	int64		force_align_i64;
  } PGAlignedXLogBlock;
  
  /* msb for char */
  #define HIGHBIT					(0x80)
  #define IS_HIGHBIT_SET(ch)		((unsigned char)(ch) & HIGHBIT)
  
  /*
   * Support macros for escaping strings.  escape_backslash should be true
   * if generating a non-standard-conforming string.  Prefixing a string
   * with ESCAPE_STRING_SYNTAX guarantees it is non-standard-conforming.
   * Beware of multiple evaluation of the "ch" argument!
   */
  #define SQL_STR_DOUBLE(ch, escape_backslash)	\
  	((ch) == '\'' || ((ch) == '\\' && (escape_backslash)))
  
  #define ESCAPE_STRING_SYNTAX	'E'
  
  
  #define STATUS_OK				(0)
  #define STATUS_ERROR			(-1)
  #define STATUS_EOF				(-2)
  #define STATUS_FOUND			(1)
  #define STATUS_WAITING			(2)
  
  /*
   * gettext support
   */
  
  #ifndef ENABLE_NLS
  /* stuff we'd otherwise get from <libintl.h> */
  #define gettext(x) (x)
  #define dgettext(d,x) (x)
  #define ngettext(s,p,n) ((n) == 1 ? (s) : (p))
  #define dngettext(d,s,p,n) ((n) == 1 ? (s) : (p))
  #endif
  
  #define _(x) gettext(x)
  
  /*
   *	Use this to mark string constants as needing translation at some later
   *	time, rather than immediately.  This is useful for cases where you need
   *	access to the original string and translated string, and for cases where
   *	immediate translation is not possible, like when initializing global
   *	variables.
   *		http://www.gnu.org/software/autoconf/manual/gettext/Special-cases.html
   */
  #define gettext_noop(x) (x)
  
  /*
   * To better support parallel installations of major PostgreSQL
   * versions as well as parallel installations of major library soname
   * versions, we mangle the gettext domain name by appending those
   * version numbers.  The coding rule ought to be that whereever the
   * domain name is mentioned as a literal, it must be wrapped into
   * PG_TEXTDOMAIN().  The macros below do not work on non-literals; but
   * that is somewhat intentional because it avoids having to worry
   * about multiple states of premangling and postmangling as the values
   * are being passed around.
   *
   * Make sure this matches the installation rules in nls-global.mk.
   */
  
  /* need a second indirection because we want to stringize the macro value, not the name */
  #define CppAsString2(x) CppAsString(x)
  
  #ifdef SO_MAJOR_VERSION
  #define PG_TEXTDOMAIN(domain) (domain CppAsString2(SO_MAJOR_VERSION) "-" PG_MAJORVERSION)
  #else
  #define PG_TEXTDOMAIN(domain) (domain "-" PG_MAJORVERSION)
  #endif
  
  
  /* ----------------------------------------------------------------
   *				Section 9: system-specific hacks
   *
   *		This should be limited to things that absolutely have to be
   *		included in every source file.  The port-specific header file
   *		is usually a better place for this sort of thing.
   * ----------------------------------------------------------------
   */
  
  /*
   *	NOTE:  this is also used for opening text files.
   *	WIN32 treats Control-Z as EOF in files opened in text mode.
   *	Therefore, we open files in binary mode on Win32 so we can read
   *	literal control-Z.  The other affect is that we see CRLF, but
   *	that is OK because we can already handle those cleanly.
   */
  #if defined(WIN32) || defined(__CYGWIN__)
  #define PG_BINARY	O_BINARY
  #define PG_BINARY_A "ab"
  #define PG_BINARY_R "rb"
  #define PG_BINARY_W "wb"
  #else
  #define PG_BINARY	0
  #define PG_BINARY_A "a"
  #define PG_BINARY_R "r"
  #define PG_BINARY_W "w"
  #endif
  
  /*
   * Provide prototypes for routines not present in a particular machine's
   * standard C library.
   */
  
  #if !HAVE_DECL_SNPRINTF
  extern int
  snprintf(char *str, size_t count, const char *fmt,...)
  /* This extension allows gcc to check the format string */
  __attribute__((format(printf, 3, 4)));
  #endif
  
  #if !HAVE_DECL_VSNPRINTF
  extern int	vsnprintf(char *str, size_t count, const char *fmt, va_list args);
  #endif
  
  #if defined(HAVE_FDATASYNC) && !HAVE_DECL_FDATASYNC
  extern int	fdatasync(int fildes);
  #endif
  
  #ifdef HAVE_LONG_LONG_INT
  /* Older platforms may provide strto[u]ll functionality under other names */
  #if !defined(HAVE_STRTOLL) && defined(HAVE___STRTOLL)
  #define strtoll __strtoll
  #define HAVE_STRTOLL 1
  #endif
  
  #if !defined(HAVE_STRTOLL) && defined(HAVE_STRTOQ)
  #define strtoll strtoq
  #define HAVE_STRTOLL 1
  #endif
  
  #if !defined(HAVE_STRTOULL) && defined(HAVE___STRTOULL)
  #define strtoull __strtoull
  #define HAVE_STRTOULL 1
  #endif
  
  #if !defined(HAVE_STRTOULL) && defined(HAVE_STRTOUQ)
  #define strtoull strtouq
  #define HAVE_STRTOULL 1
  #endif
  
  #if defined(HAVE_STRTOLL) && !HAVE_DECL_STRTOLL
  extern long long strtoll(const char *str, char **endptr, int base);
  #endif
  
  #if defined(HAVE_STRTOULL) && !HAVE_DECL_STRTOULL
  extern unsigned long long strtoull(const char *str, char **endptr, int base);
  #endif
  #endif							/* HAVE_LONG_LONG_INT */
  
  #if !defined(HAVE_MEMMOVE) && !defined(memmove)
  #define memmove(d, s, c)		bcopy(s, d, c)
  #endif
  
  /* no special DLL markers on most ports */
  #ifndef PGDLLIMPORT
  #define PGDLLIMPORT
  #endif
  #ifndef PGDLLEXPORT
  #define PGDLLEXPORT
  #endif
  
  /*
   * The following is used as the arg list for signal handlers.  Any ports
   * that take something other than an int argument should override this in
   * their pg_config_os.h file.  Note that variable names are required
   * because it is used in both the prototypes as well as the definitions.
   * Note also the long name.  We expect that this won't collide with
   * other names causing compiler warnings.
   */
  
  #ifndef SIGNAL_ARGS
  #define SIGNAL_ARGS  int postgres_signal_arg
  #endif
  
  #ifndef PASS_SIGNAL_ARGS
  #define PASS_SIGNAL_ARGS postgres_signal_arg
  #endif
  
  /*
   * When there is no sigsetjmp, its functionality is provided by plain
   * setjmp. Incidentally, nothing provides setjmp's functionality in
   * that case.
   */
  #ifndef HAVE_SIGSETJMP
  #define sigjmp_buf jmp_buf
  #define sigsetjmp(x,y) setjmp(x)
  #define siglongjmp longjmp
  #endif
  
  /*
   * We assume if we have these two functions, we have their friends too, and
   * can use the wide-character functions.
   */
  #if defined(HAVE_WCSTOMBS) && defined(HAVE_TOWLOWER)
  #define USE_WIDE_UPPER_LOWER
  #endif
  
  /* EXEC_BACKEND defines */
  #ifdef EXEC_BACKEND
  #define NON_EXEC_STATIC
  #else
  #define NON_EXEC_STATIC static
  #endif
  
  /* /port compatibility functions */
  #include "port.h"
  
  #ifdef __cplusplus
  }   /* extern "C" */
  #endif
  
  #endif   /* C_H */
  